Since the advent of fibers and textile material containing polyacrylonitrile, there has been considerable research effort toward developing dyes of improved properties for such fibers. Polyacrylonitrile fibers are those containing more than 85% polyacrylonitrile, including the well known commercially available fibers "Orlon", "Acrilan" and "Creslan". Modified acrylics are defined as containing 35 to 84% polyacrylonitrile and include the commercial fibers "Dynel" and "Verel".
It has been proposed to dye acrylic fibers with amine dyes either in the form of their salts in acid solution or their quaternary alkyl ammonium derivatives made by treating a tertiary amino group with a quaternizing agent, such as dimethyl sulfate to form a water-soluble dye which can be applied from aqueous solution. The quarterized dyes according to U.S. Pat. No. 3,480,612 have one or more of the following disadvantages:
1. They exhibit low affinity for acrylic fiber; PA1 2. They produce dyeings of poor fastness to light; PA1 3. They dye acrylic fiber in dull, unattractive shades, or PA1 4. They produce dyeings of poor levelness. PA1 X, y and Z are hydrogen, nitro, chlorine, bromine, lower alkoxy, lower alkyl, cyano, sulfamyl, N-(lower alkyl)sulfamyl, N,N-(dilower alkyl)-sulfamyl, lower acylamido, trifluoromethyl, lower alkyl sulfonyl, carbamoyl, N-(lower alkyl)carbamoyl, and N,N'-(dilower alkyl)carbamoyl; PA1 R.sub.7 is hydrogen or methyl; and PA1 R.sub.8 and R.sub.9 are hydrogen, lower alkyl, lower alkoxy, chlorine, bromine, nitro, sulfamyl, N,N-(di lower alkyl)-sulfamyl, cyano, and lower alkyl sulfonyl; PA1 R.sub.1 is lower alkyl, cyano lower alkyl, and hydroxy lower alkyl; PA1 R.sub.2, r.sub.3 and R.sub.4 are hydrogen, lower alkyl, lower alkoxy, chlorine and bromine; PA1 n is an integer having a value of 2-4; PA1 Q is a member selected from the group consisting of ##EQU1## wherein: R.sub.5 and R.sub.6 are methyl or ethyl; PA1 R is hydrogen, methyl, or ethyl; and PA1 A .sup.- is a water soluble anion.
I have discovered certain new basic azo dyes which are not subject to the foregoing disadvantages when quaternized and which in the form of the tertiary amine precursor can be applied to acrylic fibers from acid solution or to aromatic polyester textile material by conventional carrier dyeing methods.